Introduction
Waste lithium-ion batteries contain a variety of valuable materials, including iron outer shells, aluminum foils, copper foils, plastic separators, and positive and negative electrode powder. To recycle these resources efficiently and obtain high-purity metal materials, professional lithium battery crushing and sorting production lines adopt a full dry physical separation process. By making full use of the differences in magnetism, conductivity, density and particle size of various materials, the equipment can accurately separate iron, copper, aluminum and non-metallic impurities step by step, realizing scientific recycling of waste lithium batteries.
Complete Separation Process Principle
1. Multi-stage Crushing and Material Dissociation
Complete separation is based on thorough material dissociation. Waste lithium batteries first undergo coarse shredding and fine crushing treatment to break the overall battery structure. After further grinding and screening, the electrode black powder adhered to the surfaces of copper foil and aluminum foil is completely stripped off. All materials are dissociated into independent single particles, avoiding the problem of metal and powder adhesion, which lays a solid foundation for subsequent precise sorting of various metals.
2. Magnetic Separation: Independent Removal of Iron Metal
Iron materials in waste lithium batteries are mainly battery outer shells and structural accessories, which have obvious ferromagnetic characteristics, while copper, aluminum, plastics and electrode powder are non-magnetic. The crushed mixed materials first pass through a magnetic separator. The strong magnetic field of the equipment can quickly adsorb all iron impurities and realize centralized recycling of iron metals. After this process, iron is completely separated from the mixed materials, leaving copper, aluminum, plastic and powder materials to enter the next sorting link.
3. Screening and Air Separation: Remove Powder and Plastic Impurities
The mixed materials after iron removal still contain a large amount of light plastic separators and fine electrode black powder. Through vibrating screening equipment, fine powder materials are screened out and collected by negative pressure air suction system. Light plastic fragments are separated from heavy metal particles by air classification relying on air flow suspension principle. After this procedure, most non-metallic impurities are removed, and the remaining core materials are high-purity mixed copper and aluminum particles.
4. Eddy Current Separation: Purify Copper and Aluminum Mixture
Copper and aluminum are both non-magnetic and conductive non-ferrous metals. The eddy current separator generates a high-speed rotating alternating magnetic field. When conductive metal particles pass through the magnetic field, induced eddy current is generated inside the metals, forming strong electromagnetic repulsion. This principle can completely separate residual plastic, rubber and other non-metallic impurities from copper and aluminum metals, further purify the copper-aluminum mixture, and eliminate the interference of non-metallic sundries for subsequent fine separation.
It is worth noting that the eddy current separator can only separate metals from non-metals, and cannot directly separate copper from aluminum.
5. Gravity Separation: Precise Separation of Copper and Aluminum
The core difference between copper and aluminum lies in density. The density of copper is 8.9g/cm³, while the density of aluminum is only 2.7g/cm³, with a huge density gap. The gravity separator utilizes the combined action of vibration grading and adjustable air flow. According to the different sinking and floating speeds of materials with different densities, high-density copper particles sink and are collected, while low-density aluminum particles float and are discharged separately. Finally, thorough separation of high-purity copper and aluminum is realized.
Complete Process Sequence
Waste Lithium Battery Shredding & Crushing → Material Dissociation & Powder Removal → Magnetic Separation (Iron Separation) → Air Screening & Impurity Removal → Eddy Current Separation (Metal Purification) → Gravity Separation (Copper-Aluminum Separation) → High-Purity Metal Finished Products
Process Advantages
The whole production line adopts full dry physical sorting, without adding any chemical reagents, no secondary pollution, and conforms to environmental protection recycling standards. Through the collaborative operation of multiple professional equipment, the step-by-step sorting of iron, copper, aluminum and non-metallic materials is realized, with high metal recovery rate and pure finished product. It is the mainstream and efficient technical scheme for waste lithium battery resource regeneration.
Optional Upgrade Configuration
For production lines with ultra-high purity requirements, electrostatic separators and color sorting equipment can be added on the basis of the standard process. The multi-dimensional sorting mode further reduces the intermixing rate of copper and aluminum, effectively improving the purity and economic value of recycled metal products.